You do have a couple of options. firstly check and double check that you do not have a floppy disk in your PC at boot, if you have remove it.

secondly you are able to restore if you insert the origional win98 cd rom and reboot the pc.( you may need to alter the settings within the bios.
Bios
you are looking to change the boot order so that the CD rom is looked at before the hard disk.
a good order would be floppy disk cd rom then HDD.

hopefully the pc will boot to the win98 cd rom, (from memory you are given the option to repair your installation).
If you do decide to repair the operating system will reinstall from scratch, meaning that you will need to reinstall applications previously installed.

importantly user data will remain, only the operating system will be altered.

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Related Questions:

First I have to assume that you are running Windows XP. This solution should work for other versions of Windows.
The "NTLDR is missing" error displays very shortly after the computer is first started, immediately after the Power On Self Test (POST) is complete. Windows XP has only initially begun to load when the NTLDR error message appears.
Causes of NTLDR Errors
There are a number of possible causes for NTLDR errors, including the most common "NTLDR is missing" error message.
The most common reason for this error is when your PC is trying to boot from a hard drive or flash drive that is not properly configured to be booted from; in other words, it's trying to boot from a non-bootable source. This also would apply to media on an optical drive or floppy drive that you're trying to boot from.
Other possible causes include corrupt and misconfigured files, hard drive and operating system upgrade issues, corrupt hard drive sectors, an outdated BIOS, and damaged or loose IDE cables.
How to Fix NTLDR Errors
1.Restart the PC. The NTLDR error could be a fluke.

2.Check your floppy and optical (CD/DVD/BD) drives for media and disconnect any external drives. Often times, the "NTLDR is Missing" error will appear if your PC is trying to boot to a non-bootable floppy disk, CD/DVD/BD, or external hard drive or flash drive.
Note: If you find that this is the cause of your problem and it's happening a lot, you might want to consider changing the boot order in BIOS so the hard drive with Windows installed is listed first.

3.Check the hard drive and other drive settings in BIOS and ensure they are correct. The BIOS configuration tells the computer how to use a drive so incorrect settings can cause problems, including NTLDR errors.
Note: There is usually an Auto setting for hard drive and optical drive configurations in BIOS which is usually a safe bet if you're not sure what to do.

4. Restore the NTLDR and ntdetect.com files from the Windows XP CD. Restoring these two important system files from the original Windows XP CD may do the trick.

5. Repair or replace the boot.ini file. This will prevent the NTLDR error if the cause of the problem is a boot.ini file that is not configured properly for your Windows XP installation.

6. Write a new partition boot sector to the Windows XP system partition. If the partition boot sector has become corrupt or isn't properly configured, you may receive the "NTLDR is Missing" error.

7. Repair the Windows XP master boot record. NTLDR error messages may also appear if the master boot record is corrupt.

8. Reseat all internal data and power cables. NTLDR error messages could be caused by loose or malfunctioning IDE cables.
Try replacing the IDE cable cable if you suspect it might be faulty.

10. Perform a repair installation of Windows XP. This type of installation should replace any missing or corrupt files. Continue troubleshooting if this does not resolve the issue.

11. Perform a clean installation of Windows XP. This type of installation will completely remove Windows XP from your PC and install it again from scratch. While this will almost certainly resolve any NTLDR errors, it is a time consuming process due to the fact that all of your data must be backed up and then later restored.
If you can't gain access to your files to back them up, understand that you will lose them all if you continue with a clean installation of Windows XP.

12. Replace the hard drive and then perform a new installation of Windows XP. If all else has failed, including the clean installation from the last step, you're most likely facing a hardware issue with your hard drive.
NTLDR Errors Apply To
This issue applies to the Windows XP operating system, including Windows XP Professional and Windows XP Home Edition.
Windows 8, Windows 7, and Windows Vista utilize BOOTMGR, not NTLDR.
Still Having NTLDR Issues?
See Get More Help for information about contacting me on social networks or via email, posting on tech support forums, and more. Be sure to let me know what steps, if any, you've already taken to fix the "NTLDR is missing" issue.

The "NTLDR is missing", error displays very shortly after the computer is first started; after the Power On Self Test (POST) is complete. Windows XP might only initially load when the NTLDR error message appears. Causes of this error message include corrupt and misconfigured files, hard drive and operating system upgrade issues, corrupt hard drive sectors, an outdated BIOS, and damaged or loose IDE cables. Get more help and information for Windows XP hope this helps you.

Below are the full error messages that may be seen when the computer is booting.

NTLDR is MissingPress any key to restart

Boot: Couldn't find NTLDRPlease insert another disk

NTLDR is missing Press Ctrl Alt Del to Restart
Causes:

Computer is booting from a non-bootable source.

Computer hard disk drive is not properly setup in BIOS.

Corrupt NTLDR and/or NTDETECT.COM file.

Misconfiguration with the boot.ini file.

Attempting to upgrade from a Windows 95, 98, or ME computer that is using FAT32.

New hard disk drive being added.

Corrupt boot sector / master boot record.

Seriously corrupted version of Windows 2000 or Windows XP.

Loose or Faulty IDE/EIDE hard disk drive cable.

Failing to enable USB keyboard support in the BIOS.

Windows XP users

Insert the Windows XP bootable CD into the computer.

When prompted to press any key to boot from the CD, press any key.

Once in the Windows XP setup menu press the "R" key to repair Windows.

Log into your Windows installation by pressing the "1" key and pressing enter.

You will then be prompted for your administrator password, enter that password.

Copy the below two files to the root directory of the primary hard disk. In the below example we are copying
these files from the CD-ROM drive letter, which in this case is "e."
This letter may be different on your computer.

copy e:\i386\ntldr c:\copy e:\i386\ntdetect.com c:\

Once both of these files have been successfully copied, remove the CD from the computer and reboot.

I can get into the Boot First Screen but can't seem to change anything within it... These screens seems to be selectively responsive to my key presses.... I can get the bios screen up, boot order screen up but not necessarily do anything within them... e.g. I can't restart the pc using ctrl alt del when the missing NTLDR message appears.... also I have put an XP disc in and it says to press any key to BOOT from CD .... I Do so but obviously it doesn't recognise it so it gives me the missing NTLDR message again! :(